You.

What is "you", and where does it reside?

The information filter which you've acquired through a lifetime of experience. The sum of all the things you've seen, heard, felt, and thought boiled down into a lens which weaves together preconscious stimuli into the world-model you uniquely inhabit. Infinity must be down-sampled into something our finite brain matter can process. What do you miss? What do you assume which is not?

Have you ever sat stone-still for long enough to feel the sense of self-identity relax? Have you looked at outstretched hands and wondered where, precisely, in this flesh you reside? Can you pin it down?